Device for controlling the needle-bar motion and the material feed in sewing machines



Oct. 29, 1963 w. ENGEL 3,108,555

DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED INSEWING MACHINES Filed June 17, 1960 '7' Sheets-Sheet 1 Oct. 29, 1963DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED INSEWING MACHINES Filed June 17. 1960 '7 Sheets-Sheet 2 Jnven/or:

5 II. 4 9 On s 0 I M a 1/. 22 m. x m 2 ,L J T $L.L U d 2 0 2 Q 9 1:11 44 U H a l b@ \IQV r V/ I 1 7 5 E w M a 2 Oct. 29, 1963 w. ENGEL3,108,555

DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED INSEWING MACHINES Filed June 17. 1960 '7 Sheets-Sheet 3 Fig. 3

I v 71 F/ZIK 63 Oct. 29, 1963 w ENGEL 3,108,555

DEVICE FOR CONTROLLING THE NEEDLEBAR MOTION AND THE MATERIAL FEED INSEWING MACHINES Filed June 17. 1960 7 Sheets-Sheet 4' Fig.5 1+ 90Jnvenfor:

L 3,108,555 EEDLE-BAR MOTION AND Oct. 29, 1963 W. ENGE DEVICE FORCONTROLLING THE N THE MAT Filed June 17, 1960 ERIAL FEED IN SEWINGMACHINES 7 Sheets-Sheet 5 Oct. 29, 1963 w. ENGEL 3,108,555

DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED INSEWING MACHINES Filed June 17. 1960 7 Sheets-Sheet 6 Jn ven fo r:

w. ENGEL 3,108,555 DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND Oct.29, 1963 THE MATERIAL FEED IN SEWING MACHINES Filed June 17, 1960 7Sheets-Sheet 7 Jnvenfor:

United States Patent DEVICE FUR CGNTRGLLING THE NEEDLE-BAR MGTEON ANDTHE MATERIAL FEED IN EW- 1N G MACHENES Woifgang Engel, Bielefeld,Germany, assignor to Ankar- Phoenix Niihmaschinen AG, Bielefeld,Germany, a corporation of Germany Filed June 17, 1969, Ser. No. 36,934fiiairns priority, applieation Germany June 19, 1959 12 Claims. (Qt.112-158) My invention relates to zigzag sewing machines and moreparticularly to a device for controlling the lateral needle-bar motionand the material feed in such machines.

There are known zigzag sewing machines with automatic control deviceswhich, when producing fancy sewing stitches, control the position of thestitching area, the lateral stitching width and the material feed aswell as the feeding direction by means of exchangeable or se lectedcontrol cams or similar control members. The just-mentioned parameterdata, characteristic of a particular basic pattern to be producedautomatically, can be modified with the aid of a manual means forsetting the lateral stitching width, another manual means for settingthe stitching area position, and a manual means for setting the feedmotion. The manually controllable pattern modifications are madeeffective by changing the transmission ratio between the particularcontrol cams and the respective slider or crank members actuated by theappertaining cam followers. Such manually adjusted pattern modificationis possible only within the particular control range of the activecontrol cams and hence within the scope of the basic pattern determinedby the set of control cams.

Also known are manually actuable control devices which control thelateral stitching width, the stitch-area position and the amount of feedas well as the feed direction by means of a single handle adjustable inseveral setting ranges. In the known devices of this type the individualparameter data which, in the course of a fancy-stitch operation, arecontrolled in a given cyclical sequence by the just-mentioned handle,can likewise be additionally controlled by superimposed manual settingswithin the available range determined by the control cam.

However, the known automatically or manually actable control devices donot afford adjusting any desired parameter data, be it for the feed, thelateral stitching width, or the stitching-area position independentlyof, or beyond, the limitations of the basic pattern determined by thecontrol cams.

It is an object of my invention to additionally ai'iord the possibilitythat the seamstress, before commencing a sewing operation, can pre-setcertain parameter data, be it for the stitching length, the lateralstitching width, or the stitching-area position, and that she can makethe presetting become effective to interrupt or supersede the normallycam-controlled sewing operation at any desired time or stage,particularly for sewing work in which, aside from straight or zigzagstitching, certain fancy-stitch work is to be done, such ts the sewingof buttonholes or ot er closed-upon-themselves patterns. In other words,it is an object of my invention, when alternately doing such two kindsof sewing work, to make it unnecessary for each change in work toperform the inconvenient and time-consuming operations required forfirst determining and then inserting the particular control means thatcorrespond to the desired type of sewing.

It is another object of my invention to improve zigzag sewing machinesby widening the setting range available to the manual setting means, sothat the machine can be preset to any parameter values beyond the rangePatented Get. 29, 1963 ice of a particular control cam inserted or builtinto the machine.

To achieve these objects, my invention is based upon the provision of azigzag sewing machine in which the lateral stitching width, thestitch-area position, and/ or the material feed for the production offancy stitch patterns of the type closed upon themselves is controlledautomatically or manually in dependence upon the selected setting of asingle adjustable handle. According to the invention, the single handleor equivalent manual setting means in such a machine controls thetransmission memher that cooperates with the automatic cam or otherautomatic control mechanism in order to permit any desired adjustablecontrol magnitude to become effective.

This and more specific features of my invention will be described in thefollowing with reference to the embodiment of a zigzag sewing machineaccording to the invention illustrated by way of example on theaccompanying drawings in which:

FIG. 1 is a front view of the sewing machine seen from the operatorsplace.

FIG. 2 is a top view of the machine onto the plane denoted by Illl inFIG. 1, the top cover of the machine being removed.

FIG. 3 is a cross section along the line III-III in FIG. 1.

FIG. 4 is a rear view of the stitch-pattern control device which formspart of the same sewing machine.

FIG. 5 is a cross section along the vertical center plane of the controldevice according to FIG. 4, the section being taken along the line VV inPlG. 8.

FIG. 6 is a schematic and perspective bottom view of the manual controlmember for setting the position of the stitching area.

FIG. 7 is a schematic perspective view of the control device seen fromthe front, the handle for shifting the stitch area being removed.

FIG. 8 is a front view of the control device, including the handle forshifting the stitch area.

FIG. 9 shows the feed-control mechanism with the appertaining controlcam set for manual control of the material feed.

FIG. 10 shows the control cam and cam follower for controlling thestitch-area position.

FIG. 11 shows a double cam for stitching-width control, the cam beingset for manual control of the stitching width.

FIG. 12 shows the position of the same double cam in the positionoccupied during sewing of buttonholes.

FIG. 13 shows the stitch-area control cam of FIG. 10 set for sewing ofbuttonholes.

FIG. 14 illustrates the feed-control cam of FIG. 9 in the positionoccupied during sewing of buttonholes.

FIG. 15 shows details of the manual control means for setting thestitching length.

FIG. 16 is a front view and E6. 17 a partly sectional top view of themanual control means for setting the stitching direction.

The illustrated zigzag sewing machine comprises a hollow Standard andarm structure 1 (FIGS. 1, 3) in which the horizontal main shaft 2 isjournaled. The shaft 2 carries a handwheel 2a designed as a belt sheaveto be driven from a motor in conventional manner. The other end of shaft2 is linked by a crank mechanism 2b, also conventional, to thevertically reciprocable needle bar 13 of the machine. The main shaft 2is also in driving connection with a controllable mechanism, describedbelow, which causes the needle bar, while reciprocating vertically, tooscillate transversely of the material feed direction when zigzagstitches are to be produced. Such driving connection comprises a pair ofworm gears 3, 4- which connect shaft 2. with a vertical cam shaft 5(FIGS. 1, 2) journaled in a bearing 6 in the arm structure above themain shaft 2. Secured to the upper end of cam shaft is an eccentricdriver cam 7 straddled by the fork portion of a bifurcated lever 8 whoseopposite end is pivoted at 9 to the drive l ver 14} of the needle-barswing member 11. The drive lever it) is fastened to the swing member 11which is rotatable about two coaxial, pointed dowel pins 12, 12 (FIG.(.2) and which carries the vertically reciprocating needle bar 13. Asshown in FIG. 2, the fork lever 8 carries a pivot pin 14 on which aslider 15 is rotatable. The slider is displace able in a guide slot inof a guide block 17 which has a cylindrical pivot pin (not illustrated)rotatably joining the guide block with one end of a displacing lever 18.Lever 13 is rotatable about a pin 1? stationarily fastened in the armstructure it.

When the guide slot 16 of block 17 extends at a right angle to thegeometric connecting line between the respective axes of pivot pins 9and 14, the fork lever 8 will merely oscillate about the axis of pivotpin 3 due to rotation of the eccentric 7 without any displacement oflever 8 and pin 9 along the longitudinal axis of the forked lever 8.Hence the swing member 11 and the needle bar 13 are not laterallydeflected transversely of the material feeding direction. Consequently,with this positioning of the guide slot 16, the sewing machine is setfor straight stitching.

However, if t 15 position of the guide slot 16 about the pivot axis ofthe guide block 17 is changed, the fork lever 8, when being driven bydrive earn 7, not only oscillates about the axis of pivot 9 but alsoreciprocates longitudinally of the lever 8. Consequently, the swingmember 11 and the needle bar 13 now perform lateral deflections ofgreater or lesser extent in a direction transverse to that of thematerial feed, so that zigzag stitches are produced.

In order to elfect such a displacement of the guide slot 16, the guideblock 17 has an arm 34 which carries a pivot pin 33 engaging one end ofa connecting member 31. The other end of member 31 is linked by a pivotpin 32 to one arm of a bell-crank lever whose other arm is denoted by29'. The angular lever 20, 20 is rotatable on a pivot pin 19stationarily secured to the arm structure 1 of the machine.

The displacing lever 18, the arm 34 of the guide block 17, theconnecting member 31, and the arm 20 of the angular lever 20, 20 formtogether a parallelogram mechanism. Fastened to the end of the lever arm26 is a pin 26 to which one end of a connecting rod 27 is linked. Theother end of rod 27 is fastened to a connecting rod 41 by means ofscrews 43 (FIGS. 1, 2). The connecting rod 41 has an elongated slottraversed by the two screws 43 to permit adjusting the longitudinalspacing. The free end of the connecting rod 41 is linked to an angularcamfeeler lever 44 by means of a pivot pin 45 (FIGS. 2, 4). The lever 44is rotatably mounted on a pin 46 (FIG. 4) secured to a cup-shapedcarrier 47 (FIGS. 4, 5, l) which in turn is secured to the arm structure1 by screws 48, 49 (FIG. 8) and which covers a frontal opening Stl (FIG.5) of the arm structure 1.

When the guide block 17 with slot '16 is angularly displaced from itsinactive position, the sewing machine produces zigzag stitches extendingsymmetrically to the central position. If the stitching area is to bedisplaced so that zigzag or straight stitches are produced at the rightor left from the central position, the displacing lever 18 (FIG. 2) mustbe turned about the pivot pin 19. For this purpose the displacing lever18 is joined at one end with a lever arm which has a linking pin 36engaging one end of a connecting rod 39. The other end of rod 39 carriestwo screws 42 by means of which the connecting rod 43 is fastened to theconnecting rod 39. The connecting rod 49 possesses a longitudinal slot(not shown) traversed by the two screws 42 to permit adjusting therelative position of rods 39 and 44 The other end of connecting rod 44is linked by a pivot pin 51 (FIGS. 2, 4) to a cam-fceler lever 52rotatably mounted on the same pivot pin 46 as the lever Theabovementioned two adjusting means of the zigzag control device arecontrolled by handles 99 and 163 (FIGS. 5, l, 3). The handle 99 servesto manually control the lateral stitching width or to set the machineeither for zigzag or straight stitching. The handle 103, designed as aknob, permits shifting the stitching area. The machine is furtherprovided with a knob 136 (FIG. 3) adjustable to a plurality of activepositions for controlling the stitching length in the longitudinalstitching direction, and a bandle 132 for controlling the stitchingdirection, ie, to set the machine for forward or reverse stitching.Details of these four controls will be described further below. Itshould be understood, however, that while manually actuable controlmeans are shown, the machine may be additionally equipped with cammechanisms for automatically controlling the zigzag sewing operation inaccordance with a desired pattern, such automatic zigzag control meansbeing known as such and described, for example, in my copendingapplication Serial No. 7,938, filed February 10, 1960, for Zigzag SewingMachine With Fancy- Stitch Selector, assigned to the assignee of thepresent invention.

Fastened on the main shaft 2 is a belt sheave 55 (FIG. 3). Another beltsheave 57 is secured to a gripper drive shaft 58 journalled within thebottom structure 59 of the machine whose table top forms the sewingsurface for supporting the material to be sewed. A belt 56 trained aboutthe two sheaves 5'5 and 57 drives the gripper drive shaft 51 at thespeed ratio 1:1. The gripper drive shaft 58 carries an eccentric cam 60straddled by a mouth portion of a lever 61 which has one end linked by acrank pin 62 to an arm 63 fastened on a feed control shaft 64. The otherend of lever 61 carries a pivot pin 7%} on which a slider 71 isrotatable. The slider 71 glides in a slot 72 of a guide block 73 whichhas a cylindrical pin 89 (FIG. 1) rotatably mounted in the machine basestructure 59. When the guide slot 72 of block 73 extends at a rightangle to the geometric connecting line between the respective axes ofpins and 60, the fork lever 61 will reciprocate about the pivot pin 62while the arm 63 remains at rest. However, when the guide slot 72 ofblock 73 is angularly displaced from the just-mentioned position, thearm 63 and the feed control shaft 64 are caused to oscillate about theaxis of shaft 64.

The feed control shaft 64 extends parallel to the gripper drive shaft 58longitudinally of the sewing machine and up to the working range of thesewing tools in the known manner. Provided at the needle-adjacent end ofthe feed control shaft 64 is a lever arm 65 (FIG. 3) to which a feederbar 67 is linked by a pivot pin 66. The other end of feeder bar 67 has amouth portion straddling a lifting member 68. The feed motion isimparted to the material to be sewed, by means of a serrated head 69which is fastened by screws to the top portion of the bar 67. It will beunderstood that by these devices the oscillating motion of the feedcontrol shaft 64 is transmitted through the arm 65, the feeder bar 67 tothe serrated healid 69 which produces the feeding motion of the materiaTo permit turning the slot 72 of guide block 73 about the axis of pivotpin 89, the block 73 is provided with an arm 7 which carries a pin 75. Apusher rod 73 (FIG. 3) has its lower end linked to arm 74 of block 73 bymeans of pin 75. The upper end of rod 78 has a longitudinal slot 78(FIGS. 15, 16). An eccentrically mounted pin is rotatably journalled inthe hub 128 of a cam-feeder lever 127. One end of the pin 125 protrudesto the outside through a slot 134 (FIG. 17) in the wall 131 of thestandard portion of the machine arm structure. The eccentricity of thepin 125 can be set and fixed from the outside by means of a set screw129, thus making it possible to compensate for manufacturing tolerances.Fastened to the protruding end of the pin 125 by means of a set screw133 is the above-mentioned 5 handle 132 for setting the stitchingdirection (FIGS. 17, 3). The axial position of pin 1125 and pusher rod78 relative to the machine housing is secured by means of spring rings126, 13% (FIGS. 17, 15).

The cam-feeler lever 127 is rotatable on a pivot pin 135 (FIGS. 16, 17,l) fastened to the arm structure of the machine. The lever 127 has acurved portion 127a so as to straddle a pair of cams 133, 138a (FIG. 16)which serve for controlling the stitching length in the feed direction.The two cams are secured on a shaft 137 (FIGS. 16, 17, 1) which isrotatably mounted in the machine housing and which carries the manualstitchlength setting means 136 designed as a knob and provided with ascale of indicia (FIGS. 17, 3). The cams 138, 138a cooperate with twofeeler tips of the lever 127 127a. The cam contours of cams 138 and 133aare identical and are angularly displaced from each other the sameamount as the two feeler tips relative to the axis of shaft 137. In theangular position of cams 138, 138a shown in FIG. 1, the two feeler tipsabut against respective lobes of the two cam contours. With thissetting, the feeler lever 127 is in its mid-position and cannot beturned about the pin 135 by means of the stitch-direction control handle132. Now, the cipher (FIG. 3) on the indicating scale of knob 136 islocated opposite a fixed marking (not shown) on the standard portion ofthe machine housing structure and designates the inactive position, andthe other numerals designate active positions.

The cam contour of each of cams 138 and 138a, as shown in FIG. 16,recedes inwardly at a slow rate from the outermost point of the cam lobeand gradually merges with a grea er rate of directional change down tothe smallest diameter of the cam. With such a cam contour, smallstitching lengths can be adjusted very accurately as is required duringforward and reverse sewing of the sidebar (caterpillar) portions of abuttonhole. I

'Fastened to the cup-shaped carrier 47 (FIG. is a hub 93 in which ahollow shaft 94 is journalled. The shaft 24 protrudes inwardly into theinterior of the hollow arm structure 1 where it carries three cams 85,86 and 87 (FIGS. 5, 9, 11 to 14). Cam 35 coacts with a cam feeler orfollower 122 for feed control; and the two cams 86 and 87 coact withfeeler lever 44 for controlling the lateral stitching width, as morefully explained below. The opposite end of shaft 94 protrudes out of thearm structure 1 and carries a disc 98 (FIG. 5) on which a handle 99(FIGS. 5, l, 3, 7, 8) for setting the lateral stitching width ismounted. Handle 29 thus controls the cams 85, 86, 87. Coaxiallyjournalled in the bore of the hollow shaft 94 is an intermediate sleeve95 which carries a lever arm 97 (F163. 4, 5) which has a fork portionstraddling the pivot pin 46 (FIG. 4). A central pin 96 is coaxiallyjournalled in the bore of the intermediate sleeve 95 and protrudes intothe interior of the arm structure 1 where the pin 96 carries a cam 38(FIGS. 5, 7, which cooperates with a cam feeler or follower 52 (FIGS. 4,10) for controlling the position of the stitching area. The other end ofpin 96 (FIG. 5) protrudes out of the arm structure 1 and carries a knob1113 (FIGS. 5, 6, 8) fas tened by means of a set screw 1164. Turning ofknob 103 has the effect of rotating cam 88 so as to shift the centeraxis of the seam or sewing pattern being produced.

When the position of the seam (stitch-area position) is adjusted to themid-position by corresopndingly setting the knob 1113, the feeler tip115 (FIGS. 10, 4) of the feeler lever 52 is approximately in the middleof the cam portion 113 of cam 88, and the feeler tip 114 (FIGS. 4, 10)of lever 52 is approximately in the middle of the contour portion 11? ofcam 88. The cams 86 and 87 cooperate with the feeler lever 44 (FIGS. 4,11). The feeler tip 112 of feeler lever 44 presses against the cam 87,and the feeler tip 113 rests against the cam 86.

When the handle 99 for setting the size of the zigzag stitches (lateralstitching width) is in the position shown in FIG. 11, the sewing machineproduces straight stitches. When the handle 99 is turned to the right,the cam portions 120, 121 of respective cams 86 and 87 turn the feelerlever 44 and thereby vary the size of the zigzag stitches (FIG. 11). Thecam 35 (FIG. 9) does not participate in setting the stitching length byhand. For that reason the feeler tip of feeler lever 122 does not restagainst cam '85. The cam is illustrated in FIG. 9 in its inactiveposition, and in FIG. 14 in its active position.

The tfecler lever 122 (FIGS. 4, 9) for setting the stitching directionby means of the handle 132 (FIGS. 17, 3) is mounted on a pivot pin 84(FIGS. 4, 9) fastened in the cup shaped carrier 47. Likewise rotatableon pivot pin 84 is a lever 83 which carries a pin 108 protruding into acircular opening 108 (FIG. 4) of the feeler lever 122. The diameter orsize of opening 1% is larger than that of pin 108 so that the anglebetween the two levers 122 and 83 is variable within certain limits. Aspring 109 abutting against the two levers 122 and 83 has the tendencyto reduce this angle to the minimum. The spring 109 is stronger than thespring 91 (FIG. 1) and acts in opposit=ion thereto. The :lever 83carries at its peripheral end a pin 85 (FIG. 4) to which one end of apull rod 82 is linked. The other end of rod $2 engages the eccentric pin(FIGS. 15 to 17).

If the seamstress Wants to switch the sewing machine from any straightstitching or zigzag stitching to buttonhole sewing, she pulls the handle99 (FIGS. 3, 5), thus turning it about the pin 101) (FIG. 5 on disc 98in opposition to the action of the spring 123-, and subsequently, but bythe same manipulation, turns the handle about the axis of the hollowshaft 94 by about (FIG. 7). The handle 99 is extended beyond its pivot100, and the extension 102 (FIGS. 5, 7) is ring-shaped and surrounds thehollow shaft 94. The upper end of the ring-shaped extension 102 carriesa lag 101 which is biased by a spring 123 (FIG. 5) to normally engage agroove 107 (FIGS. 5, 6) in the stitch-displacing knob 103. As the handle99 is being turned about the hollow shaft 94, the lug 1G1, gliding alongthe groove 10 7 (FIG. 6), ultimately snaps into a recess 106 of knob 103due to the action of spring 123. Now the cams 85, 86, 87 and 88 areclutched together to form a single package. In this position of handle 9and cam package 85, =86, "87, 88, the feeler tips 112, 113, 114, 115 and122 (FIG. 4) are located opposite respective cam-contour portions which,during corresponding turning of the cam package 85, 86, 87, 88 by meansof the handle 99, control the lateral stitching width, the stitchingareaposition, the movement of the fabric-feeding mechanism in such a mannerthat a buttonhole is produced by virtue of the above-described angulardisplacement of the handle 99, regardless of whether the machine was andremains other-wise set for straight stitching or automatic zigzagstitching. Such buttonhole sewing proceeds as follows.

After the seamstress has latched the handle 9% with the cam package 85,86, 87, 88 in the manner described above, she turns the handle 99sequentially to dilferent angular positions corresponding to thepositions A, B, C illustrated by broken lines in FIG. 12. First thehandle 99 is set to position A where it abuts against a stop 111 (FIG.12). In this position, the cams 85, 86, 87, S8 and the feele-r levers44, 52 and 83 occupy the positions illustrated in FIGS. 12., 13 and 14;and the machine sews the left-hand side bar (caterpillar of thebuttonhole pattern while operating in reverse stitching operation. Inthis position, the cam 85 (FIG. 14) turns the feeler lever 122outwardly; and the spring 109 places the lever 83 as well as theconnecting rod 82 and hence the feeler tip of feeler lever 127 intofollower contact with the cam 138 in opposition to the acting of thespring 91. The cam 85 does not serve the purpose to set the magnitude ofthe stitching length during forward and reverse stitching, but itspurpose is to cause the feeler tips of the feeler lever 127, 127a tobecome engaged with the corresponding cams 13 8 and 1 8:: within therange of stitch sizes from approximately zero to 1 millimeter. Thisstitch size is adjustable by means of the knob 136 (FIGS. 3, 17). Theradial height of the lobe of cam 35 is so dimensioned that the feelerlever 122, when being turned outward, is lifted a sufiicient extent toplace the pin 188 approximately in the middle of the bore 108 when thefeeler tip of feeler lever 127 abuts against the contour of cam 133.

When the desired length of the buttonhole side bar (caterpillar) isreached, the seamstress, during sewing, switches the handle 99 to themid-position B for the purpose of sewing the buttonhole terminating(cross-bar) stitches. The displacing lever 13 (FIG. 2) and hence theneedle bar are now also in mid-position. This position is marked orsecured by a catch (not illustrated) in known manner, so that theseamstress can readily find this rnidposition by feel only. Now, thecams 85, 86, 87 and 38 have placed the feeler levers 44, 52 and 122 insuch a position that the sewing machine produces look stitches inforward stitching operation. In this position B of handle 99, the cam 85(FIG. 9) is turned to such an extent that the feeler lever 122 is turnedinwardly by springs 91 and 109, unimpeded by the contour shape of cam85. Such inward turning motion of feeler lever 122 takes place until thefeeler tip of feeler lever 127m, under the action of spring 91 (FIGS. 1,16), is placed into contact with the cam 138m.

After any desired number of buttonhole terminating stitches arecompleted, the seamstress places the handle to position C (FIG. 12)where it abuts against a stop 110. This causes the cams 86, 87, S8 tocontrol the feeler levers 44, 52 so that the right-hand side bar(caterpillar) of the buttonhole pattern is being sewed. Since inposition C of handle 99, the cam 85 and the feeler lever 122 arelikewise out of engagement with each other, the feeler tip of feelerlever 127a remains in engagement with cam 138a. Hence the machine againoperates with forward stitching.

This is followed by sewing the second cross bar. The seamstress nowturns the handle 99 to the mid-position B. The cams 85, 86, S7 and 83now occupy the same position as during the sewing of the first crossbar. Consequently the sewing machine, during forward feed of thematerial, produces the second group of lock stitches that terminate thebuttonhole. To prevent the last stitches from loosening, the handle 99can be turned against the stop 111 (position A) during continued sewingoperation. Then, according to FIGS. 12, 13, 14, with reverse operationof the material feeder, a few additional side-bar stitches are sewedafter the last terminating stitches are completed. Thereafter thebuttonhcle is finished.

If the seamstress wants to shift from buttonhole sewing to the sewing ofany desired straight or zigzag stitches, she pulls the handle 99 aboutthe pin 100 thus placing the lug 101 out of the range of the groove 166,and then turns the handle 99 approximately 180 about the axis of hollowshaft 94'. Thereafter buttonhole or other closed-pattern control deviceis set out of action, and the machine is again switched over for thesewing of any desired straight or zigzag stitches (FIGS. 9, i0, 11).

Consequently for switching the sewing machine from any straight orzigzag sewing to buttonhole sewing, or vice versa, only one manualcontrol member, namely the han- :dle 99, need be actuated.

I claim:

1. A zigzag sewing machine comprising reversible material feed means,guide means, a needle bar axially reciprocable in said guide means forstitching operation, said guide means being oscillatable transversely ofthe feed direction of said feed means, a control mechanism havingrotatable cam means for controlling the feed and having cam-controlledtransmission means connected to said feed and guide means for producingzigzag patterns, a con- .trol apparatus cooperating with said cam meansand transmission means for controlling the movement of said feed means,said cam means being selectively movable into respectively first andsecond conditions for respective cam control and manual sewing patterncontrol, said cam means in said first condition being operativelyengaged with said transmission means for controlling only the feedingdirection of said feed means and in said second condition beingoperatively disconnected from said transmission means, said controlapparatus comprising a manually actuable device having means forselectively adjusting said device into an inactive and a plurality ofactive posi ions for manually selectively determining the stitchinglength throughout the sewing of the pattern.

2. In a zigzag sewing machine according to claim 1, said transmissionmeans comprising cam follower means in engagement with said rotatablecam means of said zigzag pattern control mechanism when said manuallyactuable device is selectively adjusted into said active or inactivepositions, and means for disengaging said cam means and said followermeans from each other so that said cam means can be in said secondcondition and disengaged from said follower means when said manualdevice is in said active or inactive positions.

3. In a zi zag sewing machine according to claim 1, said controlmechanism comprising a first manually adjustable member for controllingthe lateral stitching width, a second manually adjustable member forcontrolling the stitching-area position, and a third manually adjustablemember for controlling the material feed, one of said manuallyadjustable members forming part of said selective adjusting device formanually setting said device to said active and inactive positionsrespectively.

4. In a zigzag sewing machine according to claim 1, said controlmechanism comprising a first manually adjustable member for controllingthe lateral stitching width, at second manually adjustable member forcontrolling the stitching-area position, and a third manually adjustablemember for controlling the material feed, said first member forming partof said selectively adjusting means for manually setting said device tosaid active and inactive positions respectively, said cam meanscomprising a first rotatable cam structure for controlling the lateralstitching width, said first cam structure being connected with saidfirst manually adjustable member to be rotated there by, said cam meansfurther comprising a second cam structure for shifting the stitchingarea, said second cam structure being coaxially rotatable relative tosaid first cam structure and being connected with said second manuallyadjustable member to be controlled thereby, a third cam structurecoaxially joined with said first cam structure to be likewise controlledby said first member, releasable latch means joining said first andsecond memers when said first member is set to a given rotationalposition relative to said second member, whereby rotation of said firstmember over a given range causes joint rotation of said first, secondand third cam structures.

5. In a zigzag sewing machine according to claim 1, said manuallyactuable device comprising two coaxial cams angularly displaced fromeach other and rotatable conjoin-tly with each other, a handle memberconnected with said two cams for setting them to a selected rotationalposition, a cam feeler member in follower engagement with both of saidcams, and a plurality of stitch parameter control members manuallyadjustable and in controlling controlling connection with said camfeeler member.

6. In a zigzag sewing machine according to claim 5, said controlmechanism comprising a first cam for controlling the stitching-areaposition, a second control cam for control of the lateral stitchingwidth, and said rotatable cam means defining a third control cam forfeed control, said transmission means having linking mechanismsconnecting said first and second control cams to said oscillatable guidemeans and having further linking mechanisms connecting said thirdcontrol cam to said feed means, said first and second and third controlcams being 9 coaxial, said third control cam having a cam followeryieldingly and operatively connected to said cam feeler member forcontrolling the latter.

7. In a zigzag sewing machine according to claim 5, comprising arotatable handle member connected with said feeler member and adiustablerelative thereto for compensation of manufacturing tolerances, a linkingmember eccentrically joined with said handle member, and rod meansconnecting said linking member with said manually aotuable device ofsaid closed-pattern control apparatus.

8. In a. zigzag sewing machine according to claim 5, comprising linkingmeans connecting said cam feeler member with said material feed meanswhereby said handle member for rotationally setting said two coaxialcams controls the stitching length through said feed means, and saidsaid manual stitch-parameter control means comprising a stitch-directioncontrol handle.

9. In a zigzag sewing machine according to claim 8, said material feedmeans comprising a drive shaft, an eccentric on said shaft and aneccentric-follower lever pivoted at one end, a slider rotatably mountedon said lever, a slide-way member in which said slider is displaceable,and a material-feeding mechanism linked to said follower lever to beoperated from said drive shaft in dependence upon the angular positionof said slide-way member, said linking means comprising a connecting rodconnecting said cam feeler member with said slide-Way member forconstrainedly adjusting the latter about its axis of rotation relativeto said lever.

10. In a zigzag sewing machine according to claim 8, comprising acontrolling connection between said feeler member and said carn followerof said third control cam for feed control, said connection includingfirst biasing spring means, said linking means between said slide-waymember and said feeler member comprising second biasing spring means,said first spring means being predominating relative to said secondspring means for overriding control.

11. A zigzag sewing machine according to claim 1, said manually actuabledevice including stitching-length setting means, said transmission meansincluding a feeler member engageable with said cam means in said activecondition of the latter, and linking means connecting said feeler memberwith said stitching-length setting means for operat-tively connectingthe latter with said feed and guide 10 means, whereby saidstitchingdength setting means can manually selectively and variablydeterminate the stitching length throughout every phase of the sewing ofsaid closed patterns.

12. In a zigzag sewing machine having a needle bar, a material feedermeans and a plurality of adjustable control members and slide blockmeans for controlling movements of said needle-bar and for controllingthe direction of movements of said material feeder means, said controlmember having rotatable cam means for controlling the feed, said cammeans being selectively movable into respectively first and secondconditions for respective cam control and manual sewing pattern control,said cam means in said first condition being operatively engaged withsaid transmission means for controlling only the feeding direction ofsaid feed means and in said second condition being operativelydisconnected from said transmission means, a manually actuable deviceselectively adjustable between an inactive and a plurality of activepositions for pre-setting given constant magnitudes for determiningmaximum movements of said feeder means, transmission I means connectingsaid adjustable control members with said slide block means forcontrolling said movements, said manually :actuable device beingoperably interposed in said transmission means between at least one ofsaid adjustable control members and said slide block means, said devicebeing under control of said one of said control members to becomeeffective in the direction determined by said one control member.

References Qited in the file of this patent UNITED STATES PATENTS(Corresponding US. 3,033,138, May 8, 1962) 564,305 Italy June 14, 1957

1. A ZIGZAG SEWING MACHINE COMPRISING REVERSIBLE MATERIAL FEED MEANS,GUIDE MEANS, A NEEDLE BAR AXIALLY RECIPROCABLE IN SAID GUIDE MEANS FORSTITCHING OPERATION, SAID GUIDE MEANS BEING OSCILLATABLE TRANSVERSELY OFTHE FEED DIRECTION OF SAID FEED MEANS, A CONTROL MECHANISM HAVINGROTATBLE CAM MEANS FOR CONTROLLING THE FEED AND HAVING CAM-CONTROLLEDTRANSMISSION MEANS CONNECTED TO SAID FEED AND GUIDE MEANS FOR PRODUCINGZIGZAG PATTERNS, A CONTROL APPARATUS COOPERATING WITH SAID CAM MEANS ANDTRANSMISSION MEANS FOR CONTROLLING THE MOVEMENT OF SAID FEED MEANS, SAIDCAM MEANS BEING SELECTIVELY MOVABLE INTO RESPECTIVELY FIRST AND SECONDCONDITIONS FOR RESPECTIVE CAM CONTROL AND MANUAL SEWING PATTERN CONTROL,SAID CAM MEANS IN SAID FIRST CONDITION BEING OPERATIVELY ENGAGED WITHSAID TRANSMISSION MEANS FOR CONTROLLING ONLY THE FEEDING DIRECTION OFSAID FEED MEANS AND IN SAID SECOND CONDITION BEING OPERATIVELYDISCONNECTED FROM SAID TRANSMISSION MEANS, SAID CONTROL APPARATUSCOMPRISING A MANUALLY ACTUABLE DEVICE HAVING MEANS FOR SECLECTIVELYADJUSTING SAID DEVICE INTO AN INACTIVE AND A PLURALITY OF ACTIVEPOSITIONS FOR MANUALLY SELECTIVELY DETERMINING THE STITCHING LENGTHTHROUGHOUT THE SEWING OF THE PATERN.